Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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"PULL THROUGHS"
THE CURRENT INVENTION
The present invention relates to a pull through and related methods of
manufacture, use and dispensing. In one form, such a pull through is an
endoscope pull
through or cleaning apparatus, and the present invention also provides a
method of
manufacturing such an endoscope cleaning apparatus.
Endoscopes require frequent cleaning. It is found that endoscopes (such as
those
lined with, for example, a polyurethane sleeve) are perhaps best sterilised
between uses
by a cleaning regime that involves the pushing and/or pulling through of a
brush the
effect of which is to smooth the inwardly directed surface and surface
deposits of the
polyurethane sleeve or its equivalent. Apparently this better enables chemical
cleaning
and sterilisation to ensue. See for example the post 2 March 2000 published
content of
PCT/AU99/00669 (WO 00/10476) ofNovapharm Research (Australia) Pty Limited.
SUMMARY OF THE INVENTION
The present invention is directed to any such pull through apparatus, all uses
of
such apparatus and methods for manufacturing such apparatus.
As used herein the term "pull through" also includes (where the circumstance
allows) a "push through" device. Frequently, by way of example, where a short
length
conduit is to be dealt with, it is sometimes just as convenient to push the
head of a pull
through type device through the device rather than thread and then pull the
pull through
device through the short length conduit. Accordingly the term "pull through"
in the
present specification and in the appended claims includes within its ambit any
variant
capable in some circumstances of being used as a push through.
In a first aspect the invention is a pull through comprising or including
a filament having at least a thermoplastics surface, and
a moulded thermoplastic mass about said filament defining a pull through
profile
adapted for the purpose of the pull through,
wherein the filament is a monofilament (whether of the one material or
otherwise) sufficiently stiff to enable its threading through the member (e.g.
endoscope,
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fuel line, conduit, barrel, etc.) for which it is adapted or intended for use,
and wherein said moulded thermoplastic mass is of a material of lower melting
point than at least part of said filament.
Preferably said monofilament is of a single plastics material.
Preferably said single plastics material is polypropylene.
Preferably the moulded thermoplastics mass is of polyethylene (eg; LLDPE) and
a polyolefin elastomer. Examples include SANTOPRENETM, DOWLEXTM and
ENGAGETM.
Preferably said filament is round in section.
Preferably said moulded thermoplastics mass is adjacent one end of said
filament.
Preferably said moulded thermoplastics mass has been injection moulded about
said filament only once the thermoplastics surface of said filament onto which
it is to
be injection moulded has been softened and/or conditioned.
Preferably said filament is substantially straight and free of any previous
spool
or coil memory.
Preferably said filament is conditioned by heating prior to said mass being
injection moulded.
Preferably said filament is conditioned by heating and stretching prior to
said
mass being injection moulded.
Preferably said filament is a monofilament of polypropylene that has been
heated
preferably to from 91 to 95 C (e.g. 93 to 95 C) for preferably from 8 to 15
seconds (e.g.
about 12 seconds) whilst preferably being stretched axially preferably by from
1 to 5%
of its length from a feeder spool or coil.
Preferably said polypropylene monofilament has been extruded whilst including
a gas generating agent which will expand the core region thereof upon die
emergence.
Preferably said gas generating agent releases CO2.
Preferably said gas generating agent inclusion is such as to enhance the
circularity of cross-section of the monofilament from the extrusion die.
Preferably said mass is of a profile (which whilst it may differ axially with
respect to the filament) is laterally preferably symmetric about said
filament.
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In another aspect the invention is an endoscope pull through, being a pull
through as previously defined.
In yet another aspect the invention is a conduit pull through, being a pull
through as previously defined.
In another aspect the invention is a method of manufacturing a pull through,
said pull through comprising or including
a filament having at least a thermoplastics surface, and
a moulded thermoplastic mass about said filament defining a pull through
profile
adapted for the purpose of the pull through,
said method comprising or including
providing a coil or spool feeding of a monofilament filament having at least a
thermoplastic surface
conditioning the coil or spool feed filament at an elevated temperature whilst
under axial tension so as to reduce coil or spool memory in the filament, and
injection moulding a thermoplastic pull through profile about at least one
axial
zone of said filament, said injection moulding being with a molten
thermoplastic
capable of "keying" to the surface of the monofilament at a temperature below
the
melting point of the filament.
In another aspect the present invention consists in a pull through useably as
endoscope cleaning apparatus said apparatus comprising or including
an elongate member capable of being inserted in part through a conduit (e.g.
an
endoscope and thereafter to be pulled fully therethrough, said elongate member
being
at least in part of a first plastics material or first plastics materials
(hereafter "first
plastics material"), and
an injection moulded form carried at and/or adjacent one end of said elongate
member, said form being of a second plastics material or second plastics
materials
(hereafter "second plastics material") and being such as to provide a
smoothing and/or
cleaning effect upon its pull through of the conduit (e.g. an endoscope) of
appropriate
configuration and/or dimension,
wherein the form of said second plastics material has been injection moulded
onto said first plastics material of said elongate member, the melting point
of said
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second plastics material being less than that of said first plastics material.
As used herein "melting point" in respect of the first plastics material
and/or
second plastics material includes melting of the material or, if a blend,
melting of
sufficient material thereof.
Preferably said elongate member is preferably a string like member.
Preferably said elongate member is at least substantially formed of a suitable
plastics material.
Preferably said suitable plastics material is at least 50% PP (polypropylene).
Preferably said elongate member is a monofilament.
Preferably said monofilament is 100% PP albeit (optionally blown by a blowing
agent thereby to assume a better roundness in cross-section).
Optionally said suitable plastics material for the elongate member is 50% HDPE
and 50% PP by weight as a blend or a coaxial make up of a single monofilament.
Preferably said injection moulded form is of a thermoplastic material having a
melting point less than that of the first plastics material or the material
providing at least
the axial strength region of said elongate member.
Preferably the two plastics material are such as to enable some degree of
melding, the melting point differential between the two plastics materials
lending
themselves to that outcome.
Preferably the second plastics material in an clastomer with LLDPE.
In another aspect the present invention consists in endoscope cleaning
apparatus substantially as hereinafter described witli reference to the
accompanying
drawings.
In still a further aspect the present invention consists in a method of
manufacturing endoscope cleaning apparatus in accordance with the present
invention which comprises or includes taking or providing an elongate member
as
aforesaid and thereafter injection moulding on or adjacent (or both) one end
thereof said
injection moulded form, said injection moulded form being ofa second plastics
material
of lower melting point than the plastics material of that region (at least) of
said elongate
member on which the moulded form is injected.
In another aspect the present invention consists in endoscope cleaning
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apparatus prepared by a method in accordance with the present invention.
In still a further aspect the present invention consists in use of apparatus
in
accordance with the present invention to clean an endoscope or endoscopes.
In another aspect, the present invention resides in a pull through comprising
or
including a filament having at least a thermoplastics surface, and a moulded
thermoplastic
mass about said filament defining a pull through profile adapted for the
purpose of the pull
through, wherein the filament is a monof lament sufficiently stiff at ambient
temperature(s)
to enable its threading through a conduit, passageway or the like of a member
for which it is
adapted or intended for use, and wherein said moulded thermoplastic mass is of
a material of
lower melting point than at least part of said filament.
In a further aspect, the present invention resides in a pull through useably
as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at or adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing or cleaning effect upon its pull through of the conduit
of appropriate
configuration or dimension, wherein the form of said second plastics material
has been
injection moulded onto said first plastics material of said elongate member,
the melting
point of said second plastics material being less than that of said first
plastics material.
In another aspect, the present invention resides in a pull through useably as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at and adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing or cleaning effect upon its pull through of the conduit
of appropriate
configuration or dimension, wherein the form of said second plastics
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material has been injection moulded onto said first plastics material of said
elongate
member, the melting point of said second plastics material being less than
that of said first
plastics material.
In a further aspect, the present invention resides in a pull through useably
as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at or adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing and cleaning effect upon its pull through of the
conduit of
appropriate configuration or dimension, wherein the form of said second
plastics material
has been injection moulded onto said first plastics material of said elongate
member, the
melting point of said second plastics material being less than that of said
first plastics
material.
In another aspect, the present invention resides in a pull through useably as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at or adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing or cleaning effect upon its pull through of the conduit
of appropriate
configuration and dimension, wherein the form of said second plastics material
has been
injection moulded onto said first plastics material of said elongate member,
the melting
point of said second plastics material being less than that of said first
plastics material.
In a further aspect, the present invention resides in a pull through useably
as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
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at and adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing and cleaning effect upon its pull through of the
conduit of
appropriate configuration or dimension, wherein the form of said second
plastics material
has been injection moulded onto said first plastics material of said elongate
member, the
melting point of said second plastics material being less than that of said
first plastics
material.
In another aspect, the present invention resides in a pull through useably as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at and adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing or cleaning effect upon its pull through of the conduit
of appropriate
configuration and dimension, wherein the form of said second plastics material
has been
injection moulded onto said first plastics material of said elongate member,
the melting
point of said second plastics material being less than that of said first
plastics material.
In a further aspect, the present invention resides in a pull through useably
as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at or adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing and cleaning effect upon its pull through of the
conduit of
appropriate configuration and dimension, wherein the form of said second
plastics material
has been injection moulded onto said first plastics material of said elongate
member, the
melting point of said second plastics material being less than that of said
first plastics
material.
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In another aspect, the present invention resides in a pull through useably as
endoscope cleaning apparatus said apparatus comprising or including an
elongate member
capable of being inserted in part through a conduit and thereafter to be
pulled fully
therethrough, said elongate member being at least in part of a first plastics
material or first
plastics materials (hereafter "first plastics material"), and an injection
moulded form carried
at and adjacent one end of said elongate member, said form being of a second
plastics
material or second plastics materials (hereafter "second plastics material")
and being such as
to provide a smoothing and cleaning effect upon its pull through of the
conduit of
appropriate configuration and dimension, wherein the form of said second
plastics material
has been injection moulded onto said first plastics material of said elongate
member, the
melting point of said second plastics material being less than that of said
first plastics
material.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred form of the present invention will now be described with reference
to the
accompanying drawings in which;
Figure 1 is a reduced view of a preferred form of the present invention having
an
injection moulded form of said second plastics material at the end of a pull
through type
filament of said first plastics material, said pull through elongate member
being preferably
flexible and being able to pull the brush like form of the injection moulded
form to achieve a
cleaning effect in an appropriately dimensioned endoscope,
Figure 2 is a cross section along the longitudinal axis of the injection
moulded form
end of the cleaning apparatus of Figure 1,
Figure 3 shows some alternatives to the embodiment of Figure 2, and
Figure 4 shows a preferred manufacturing sequence.
In the preferred form of the present invention the pull through is a cut to
length
straight and threadable monofilament of a suitable polypropylene. Preferably a
tempered
extruded polypropylene (eg; homopolymer P.P. supplied by Fina Chemicals,
Europe or
Honam Petrochemical, Korea) that has a CO2, blown section (as a result of
there having
been foaming agents included with the polypropylene at the extrusion stage
thereof)
provides the monofilament, such monofilament assurning a substantially round
cross
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section. Whilst coaxially different materials may be used that is not a
preferred option and
nor is blended material owing to delamination. Delamination problems may be
overcome
by better compounding prior to extrusion.
PP monofilament produced on single screw extruder 5 zones reverse temperature
profile.
Polymer Base - Polypropylene homopolyer MFI 3.5
Additives - Hydrocerol foaming agent let down into LDPE base.
Colour fluoro red let down into LLDPE base / Food contact safe.
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Processing Data:
Polymer and additives are pre-mixed. Additive percentages are precise.
Processing through the extruder using the correct temperature allows a
controlled
Carbon Dioxide release in the centre of the extrudate when extruded through
the nozzle
and exposed to the pressure drop in the atmosphere for a short time before
being
quenched, extrudate is drawn away from the die nozzle at a precise constant
speed
before being reheated in hot air.
Once the extrudate has been reheated it is then pulled down many times faster
than the extrusion speed thus forming molecular chains which results in the
extrudate
becoming strong in the longitudinal direction. In doing this, lateral strength
is
extensively reduced and the extrudate remains stressed. The surface of the
extrudate is
then heat treated under tension to biaxially orientate the surface molecules
of the
extrudate before being precision cross wound to a diameter of 130mm approx on
a PVC
core. The product is shrink wrapped for transportation and hygiene purposes.
The most preferred plastics material is a homopolymer polypropylene supplied
by Finapro Chemicals or Honan.
That product with an inclusion of hydrocerol CO, is extruded to provide a
monofilament of density about 0.97. Extruded PP filament tempered at about 130
C
is 0.9mm ( 5%) in diameter.
Conditioning:
Because the extrudate is packaged hot and stressed, it takes on a very acute
memory. Annealing or reheating the extrudate below a temperature less than the
softening point of the polymer under light tension allows the molecules in the
extrudate
to relax thus eliminating the memory. A consequence of such conditioning is
that the
product will shrink.
The pre-conditioning tunnel is a simple heat tunnel during which the
monofilament is drawn under some degree of tension (preferably from 91 to 95
C(most
preferably 93 to 95 C) for about 12 seconds) so as to achieve an axial
extension of no
greater than 5% but preferably more than 1% during such conditioning).
The monofilament itself has a pull through head profile of a suitable material
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injection moulded there around at a temperature not sufficient to melt the
monofilament
(at least in total) at that point (or those points) and preferably not at all.
Whilst ideally the surface of the polypropylene monofilament has been pre-
conditioned at an elevated temperature in order to take away the memory of its
spool
or coil supply, such preconditioning temperature is sufficient only to soften
the outer
surface to ensure better keying with the material and not to detract from the
prior higher
temperature tempering of the monofilament to prevent "fluffiness".
In the preferred form of the present invention the arrangement is as shown in
Figure 4 where the injection moulding is performed using any appropriate
injection
moulding machine (for example, a BOYTM 22AVV) and a cassette or other off take
of
the output product bundles.
In another embodiment of the present invention (much less preferred as less
easily threaded and more prone to delamination) the elongate element 2 may be
of a
suitable plastics material (such as 50% HDPE and 50% P.E.). Such a HDPE/PP
blend
has when formed and stretched a uniaxial orientation and at that end of the
filament 1
onto which the injection moulded form 2 is injection moulded there is a
material
melting point greater than that of the injection moulded form material.
The injection moulded form 2 however is of a thermoplastic capable of being
injection moulded. Such materials include a combination of an elastomer and
LLDPE
and preferably have a melting point below that of the material 1 so as to not
destroy the
structure of the filament 1 and thus the integrity of the composite device.
In the preferred form of the present invention therefore preferably the
monofilament is either a polypropylene or a polypropylene/high density
polyethylene
mix. The head is preferably a linear low density polyethylene/elastomer mix
but
alternative could be of elastomer alone, high density polyethylene alone or
TPR.
The pull throughs thus made can have the pull through profile of any
appropriate
form but preferably one that is symmetric about the monofilament into which it
is
keyed.
To assist such moulded symmetry of the pull through head preferably the
waisted
region of the filament (see Figure 2) is support on a pin or the like member
in the mould
cavity.
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Whilst annular flutes or the like can be provided these need not necessarily
be
present. Moreover for purposes other than endoscope cleaning or smoothing
purposes
other forms (brush-like or not) can be prepared.
A person skilled in the art will appreciate how (as shown) injection moulded
form 2 can be brush like in character (whether having continuous or
discontinuous
annular ridges or the like being provided to exert a cleaning or smoothing
effect).
The dimensions will be as varied as are the dimensions (diameter and length)
of,
for example, endoscopes.
For usual endoscope purposes an ideal length of a pull through is from 30 to
220
cm with the pull through profile being of a circular cross-section at its
maximum
dimension with such diameter being in the range of from 0.95 to 4.5 mm.
Other uses to which such pull throughs can be put include the cleaning of fuel
lines, the cleaning of firearms, etc.
In use the pull through filament 1 would be inserted into the conduit to be
pulled
through (e.g. an endoscope, a fuel line, etc.) and thereafter the head 2 would
be pulled
through using the filament 1.
